<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      .score-case {
        width: 1000px;
        margin: 50px auto;
        display: flex;
      }
      .score-case .table {
        flex: 4;
      }
      .score-case .table table {
        width: 100%;
        border-spacing: 0;
        border-top: 1px solid #ccc;
        border-left: 1px solid #ccc;
      }
      .score-case .table table th {
        background: #f5f5f5;
      }
      .score-case .table table tr:hover td {
        background: #f5f5f5;
      }
      .score-case .table table td,
      .score-case .table table th {
        border-bottom: 1px solid #ccc;
        border-right: 1px solid #ccc;
        text-align: center;
        padding: 10px;
      }
      .score-case .table table td.red,
      .score-case .table table th.red {
        color: red;
      }
      .score-case .table .none {
        height: 100px;
        line-height: 100px;
        color: #999;
      }
      .score-case .form {
        flex: 1;
        padding: 20px;
      }
      .score-case .form .form-item {
        display: flex;
        margin-bottom: 20px;
        align-items: center;
      }
      .score-case .form .form-item .label {
        width: 60px;
        text-align: right;
        font-size: 14px;
      }
      .score-case .form .form-item .input {
        flex: 1;
      }
      .score-case .form .form-item input,
      .score-case .form .form-item select {
        appearance: none;
        outline: none;
        border: 1px solid #ccc;
        width: 200px;
        height: 40px;
        box-sizing: border-box;
        padding: 10px;
        color: #666;
      }
      .score-case .form .form-item input::placeholder {
        color: #666;
      }
      .score-case .form .form-item .cancel,
      .score-case .form .form-item .submit {
        appearance: none;
        outline: none;
        border: 1px solid #ccc;
        border-radius: 4px;
        padding: 4px 10px;
        margin-right: 10px;
        font-size: 12px;
        background: #ccc;
      }
      .score-case .form .form-item .submit {
        border-color: #069;
        background: #069;
        color: #fff;
      }
    </style>
  </head>
  <body>
    <div id="app" class="score-case">
      <div class="table">
        <table>
          <thead>
            <tr>
              <th>编号</th>
              <th>科目</th>
              <th>成绩</th>
              <th>操作</th>
            </tr>
          </thead>
          <tbody v-if="list.length > 0">
            <tr v-for="(item,index) in list" :key="item.id">
              <td>{{ index+1 }}</td>
              <td>{{ item.subject }}</td>
              <td :class="{ red:item.score<60}">{{item.score}}</td>
              <td><a @click.prevent="del(item.id)" href="#">删除</a></td>
            </tr>
          </tbody>
          <tbody v-else>
            <tr>
              <td colspan="5">
                <span class="none">暂无数据</span>
              </td>
            </tr>
          </tbody>

          <tfoot v-if="list.length">
            <tr>
              <td colspan="5">
                <span>总分:{{ total }}</span>
                <span style="margin-left: 50px">平均分:{{ avg }}</span>
              </td>
            </tr>
          </tfoot>
        </table>
      </div>
      <div class="form">
        <div class="form-item">
          <div class="label">科目：</div>
          <div class="input">
            <input
              type="text"
              placeholder="请输入科目"
              v-model.trim="subject"
            />
          </div>
        </div>
        <div class="form-item">
          <div class="label">分数：</div>
          <div class="input">
            <input
              type="text"
              placeholder="请输入分数"
              v-model.number="score"
            />
          </div>
        </div>
        <div class="form-item">
          <div class="label"></div>
          <div class="input">
            <button class="submit" @click="add()">添加</button>
          </div>
        </div>
      </div>
    </div>
    <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
    <script>
      const app = new Vue({
        el: "#app",
        data: {
          list: [
            { id: 1, subject: "语文", score: 20 },
            { id: 7, subject: "数学", score: 99 },
            { id: 12, subject: "英语", score: 70 },
          ],
          subject: "",
          score: "",
        },
        computed: {
          total() {
            return this.list.reduce((sum, item) => sum + item.score, 0);
          },
          avg() {
            if (this.list.length === 0) {
              return 0;
            }
            return (this.total / this.list.length).toFixed(2);
          },
        },
        methods: {
          del(id) {
            console.log(id);
            this.list = this.list.filter((item) => item.id !== id);
          },
          add() {
            if (!this.subject) {
              return alert("请输入正确的科目");
            }
            if (
              (typeof this.score !== "number") |
              (this.score < 0) |
              (this.score > 100)
            ) {
              return alert("请输入正确的分数");
            }
            this.list.unshift({
              id: +new Date(),
              subject: this.subject,
              score: this.score,
            });
          },
        },
      });
    </script>
  </body>
</html>
